You bet your sweet Bippy I do!
Seriously, yes, I am a bit OCD about it. But if my shampoo is leaked out, I have a lot less product for my trip, even after smooshing the shampoo filled ziplock on my head!
I am pretty fastidious about packing and place anything that could leak in a ziplock bag. I mean, even my hairspray! I do have a plastic lined pocket in my toiletries bag and a leak of shampoo was pretty mess in that, but it was detachable and I could rinse it out. But I lost a lot of shampoo.
You and I must be kindred spirits!
You could go to any one of my suitcases right this minute, whether carry-on or pullman bag, and I have a variety of sizes of ziplock bags, at least a dozen in each bag, from snack size to sandwich size, quart, gallon, and yes! 3 gallon size!!. Lots more than that if it's a trip of more than 2-4 days!
I find ziplocks to come in handy for SO many things!